Induction-motor.



No. 843,981. PATENTED FEB. 12, 1907.

' E. (I. WILLIS. INDUCTION MOTOR.

APPLICATION FILED NOV.9, 1905. A

3 SHEETS-SHEET 1.

No. 843,983.. PATENTED PEB. I2, 1907. E. J. WILLIS.

INDUCTION MOTOR.

APPLICATION FILED NOV. 9, 1905.

3 SHEETS-SHEET 2.

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No. 843,981. PATBNTBD FEB. i2, 1907. E. J. WILLIS.

NDUGTIoN MOTOR.

APPLICATION FILED NOV.9, 1905.

, 3 SHEETS-SHEET 3. Phasef P-aee 7 0`I 7/ Y 7z- 6/ ma u 7550 7AM' i dJ1 6.9

- efficient running condition after being startnecting the starting-coils in series with the invention. Fig. 2 is an elevation of a portion UNITED sTATiis PATENT .orrron EDWARD J. VILLIS, OF RICHMOND, VIRGINIA.

. AINDucrloN-wloroa.

T0 rtl/ 'wh/0m it may concern.'

Be it known that I, EDWARD J. WILLIs, a citizen of the United States, residing at Richmond, in the county of Henrico and State of Virginia, have invented certain new Aand useful Improvements in Induction-Motors, of which the following is a Specification.

This invention' relatesY to a new method of starting and operating induction-motors and to a motor of improved construction which is particularly well adapted for operating in accordance with the principles of said method.

The objects of my invention are to provide for easily and economically starting induction-motors and for maintaining them in an ed. These objects are accomplished in the practice of my invention by the use in the manner hereinafter described of startingcoils which,may be of relatively high resistance in addition to runnin .,-coils wound to correspond to usual formu as, ,whereby any selected voltage can be thrown upon the motor at the time of starting and the motorrun after starting with the maximum economy and eiiiciency. Means are provi ed for conrunning-coils when itis desired to start the motor and for cutting the starting-coils out of circuit after the motor has beenf-airly started, thus enabling the full voltage to pass directly to the running-coils, and thereby cient running condition.

With these and other objects in view the present invention consists in the combination and arrangement of parts, as will be hereinafter more fully described, shown in the accomp anying drawin s, and particularly pointed out in the appen ed claims.

In the accompanying drawings, Figure 1 is an end elevation of a portion of an inductionmotor constructed in accordance with the of the stator of an induction-motor, illustrating the arrangement of the starting and running coils. Fig.I 3 is a diagrammatic view illustrating the winding of a single-phase motor when constructed in accordance with Specification of Letters Patent.

Application filed November 9,

' at will.

ywhen the motor is to be started the switch the invention. Fig. 4 is a diagrammatic view illustrating the winding of a two-phase motor when constructed in accordance with l the invention. Fig. 5 is a diagrammaticl view illustrating the method of winding a threehase motor, said winding being arrange in accordance with what is known as Patented Feb. 12, 1907.

1905. Serial No. 286,536.

a three-phase Y system. Fig. 6 is a diagrammatic view illustrating a methodof winding a three-phase motor,said winding being arranged in accordance with what is known as a three-phase delta system, and

Fig. 7 is a A diagrammatic view further illustrating the winding of thestatorof a threephase delta connected motorwhen construct- Ved in accordance with the invention.

Referring to the drawings, the numeral 5 designates the frame of an induction-motor, which is supported on legs f6. Mounted within the frame 5 is a stator 7, composed of the usual punched laminae 8, said laminae being punched in such manner as to form radial recesses 9 therein. It will be readily understood that these recesses 9 form transverse channels 10 in the vstator when the laminae forming said stator have been assembled. This construction is well known and forms no Jpart of the present invention beyond the act that recesses 9 are made deep enough to receive not only the usual runningcoils 11, formed of comparatively large wire of relatively low resistance, but also to receive starting-coils 12, which may be formed, as shown, of small wire of relatively high resistance. Starting-coils 12 are arranged in the bottoms of the channels 1() beneath the running-coils 11, whereby the magnetic leakage from said last-named coils may be reduced to a minimum.

In Fig. 3 the method of arranging the winding of a single-phase motor is diagrammatically illustrated. Referring particularly to said figure, the numeral 13 designates the base-plate of an ordinary double-throw knife-switch. pivotedto the terminals 14 and 15, and the running terminals 16 and 17 and the starting terminals 18 and 19 are so arranged that terminals 14 and 15 may be connected to terminals 16 and 17 or to terminals 18and 19 It will therefore be seen that if is thrown into such position as to connect the terminals 14 and 15 to the terminals 18 and 19 the circuit between the motor-coils and the line-wires 20 and 21, which are connected vto terminals 14 and 15, will be completed as follows: The current from terminal 14 will pass through wire 22 to one of the running-coils 11, thence through wire 23 to a second running-coil, thence through wire 24 to one'of the starting-coils 12, thence l through wire 25 to a second starting-coil,

The blades of said switch are IOO thence through wire 26 to terminal 1.9, and through the switch-blades t-o terminal 15. After the motor has been fairly started the switch may be moved to bring the terminals 14 and 15 into connection with the terminals 16 and 17, which will result in cutting out the starting-coils and permitting the current to pass unrestrictedly to the ruiming-coils through the following circuit: from contact 14 to contact 16, thence through wire 27 to contact 18, thence through the connections hereinbefore described to both of the running-coils. A wire 28completes thc circuit 'from the second running-coil to terminal 17, it being oi" course understood that at this time the switch-blade makes connection between terminals 15 and 17 Referring now to Fig. 4 of the drawings, the numeral 29 designates the base-plate of a four-blade knife-switch. Wounted upon the base are the contact-points 30, 31, 32, and 33, upon which the blades ot' the switch are pivoted. lJine-wires-34, 35, 36, and 37 are connected to said terminals. The wiring about to be set forth is for a two-phase motor. Starting contact-points 3S, 39, 40, and 41 are also mounted upon base 29. lVhcn it is desired to start the motor, the switch is thrown into osition to connect the points 30,31, 32, an 33 with vthe starting-points 38, 39, 40, and 41, at which time thc circuit will be completed through line-wire 34, through one of the. blades of the switch to contactpoint 38, thence through wire 42 to a running-coil 11, thence through a starting-coil 12 and wire 43 to contact-points 39 and 31. At the same time a circuit is formed through line-wire 36, contact-points 32 and 40, and wire 44 to a running-coil 11 of the second phase. Said circuit is completed through the starting-coil of the second phase, wire 45, and contact-points 41 and 33 to line-wire 37. After the `motor has been fairly started the switch is moved to connect the contactpoints 30, 31, 32, and 33 with ruiming contactpoints 46, 47, 48, and 49, at wl'iich time the circuit of the rst phase is as follows: through line-wire 34, contact-points 3() and 46, Wire'50, contact-point 36, wire 42, running-coil 11, wire 51, and contact-points 47 and 31 to line-wire 35. The circuit of the second `phase is as follows: through line- Wire 36, contact-points 32 and 48, wire 52, contact-point 40, wire 44, running coil 11, and Wire 53 and contact-points 49 and 33 to line-wire 37. It will be seen that at this time the starting-coils will not he in series with the running-coils, and said running-coils alone will be in circuit with the line-wires.

. As has been hereinbefore stated, the diagrammatic View, Fig. 5, illustrates a threephase af-winding i"or an induction-1 notor pro- 'vided with the starting and runningcoils hereinbefore mentioned. 1n this figuretliel reference-numeral 54 designates the basevmounted upon said plate 69.

plate ol'A a three-blade knife-switch. Lincwires 55, 56, and 57 are connected to contactpoints 58, 59, and 60. Running contactpoints 61, 62, and 63 are mounted upon said lese-plate, as are also mounted the contactpoints 64, 65, and 66. As will be readily understood from the drawings, when the contacts 61, 62, and 63 are connected by the switch-blades to contacts 58, 59, and 60 the current may pass through. wires 67 directlT to the running-coils 11 g but when the switch is shifted to bringpoints 64, 65, and 66 into connection with points 5S, 59, and 60 the current must pass through wires 68 and starting-coils 12. as well as the running-coils.

Fig. 6 illustrates the arrangement ol: coils in a three-phase delta system ol" winding induction-motors. ln said ligure the numeral 69 designates the base-plate oi a threeblade electric switch. Line-wires 70, 71, and 72 are connected. to contact-points 73, 74, and 75, secured to said base-plate. Running contact-points 76, 77, and 7S and starting contact-points79, 80, and S1 `are also As willbe seen from the drawings, when contact-points 73, 74, and 75 are connected to points 76, 77, and 78 the current ma)v pass trom the linewires 70, 71, and 72 directly to the runningcoils 1.1 through the wires S2, S3, and S4; but when thc switch is shittcd to bring the points 73, 74, and 75 into connection with startingpoints 79, 80, and 81 the current must pass through wires 85, 86, and S7, and the start- -inOf-coils 12, as well as the running-coils 11.

n Fig. 7 the winding oi a three-phase motor has been carried out throughout the diagrammatically-illustrated stator. The switchboard and leads are substantially the same as illustrated in Fig. 5, the startingcoils being, however,v represented by dotted lines and the running-coils by full lines. From the description oi' Fig. 6 the diagram shown in Fig. 7 will be readily understood. The starting-coils are arranged in series with the running-coils. Take the winding of phase three, lor instance. One end, but not the incoming lead of the starting-coils, is connected to the incoming lead of the running-coils at 90, so that the current from the starting lead will pass through the startingcoils and running-coils before passing out of the motor at terminal 90, while current from the incoming lead of' the running-coils passes directly to running-coils without passing through the starting-coils.

While it is a preierred embodiment of my invention to have the starting-coils wound in a similar manner to the running-coils, difiering therefrom only in the number of turns, as illustrated in Fig. 7, it is to be understood that my invention is of a generic character,

as particularly pointed out in the appended claims. coils -in series with the running-coils, as here- IIO The result of arranging the startingat rest, is prevented, and improved means for starting said motor are provided.

While the method of arran ing the wiring shown and described is well ad the purposes set forth, it is to be understood `that the invention is not limited thereto, but

that such changes as may be made Within the scope of the ap ended claims ma be resorted to without departing from sai invention.

Having thus described my invention, what I claim as novel, and desire to secure by Letters Patent, is

1. An induction-motor having a slottedstator running-coils of relatively large wire disposed within the slots of said stator, starting-coils of relatively small wire also disposed within the slots of said stator, and means for throwing said starting-coils into or out of series with the running-coils.

2. An induction-motor havmg a slotted stator, starting-coils disposed Within the slots of said stator and at one end of said slots, running-coils similarly wound and disposed in the same manner within another apted to serve portion ofthe lsaid slots and at the opposite end thereof, and means for throwin the starting-coils into and out of circuit the running-coils. v

3. A polyphase induction-motor having a slotted stator,- starting-coils disposed Within a portion of the slots thereof, running-coils similarly Wound and disposed in the same manner within another portion ofthe said slots and means for throwing the starting'` coils into and out of circuit with the runningcoils.

4. A polyphase induction-motor having a' stator provided with slots therein extendm outward from the central portion thereo starting-coils disliosedwithiri the outer portion of said slots and running-coils similarly wound and disposed ,in the-Samet manner within the inner portion of sai slot. v J

5. A polyphase induction-motor'having a stator provided with slots extending outward from the central portion thereof, start- 'ing-coils of relatively small wire disposedwithin the outer portion of said slots and running-coils of relatively large wire simi. larl wound anddisposed in the same manner wit the inner portion of said slots.

In testlmony whereof I affix my signature witnesses.

in presence of two EDWARD J. WILLIS.

Witnesses:

W. BRYDON TENNANT,

M. J. TRAYLOR. 

